Dental handpiece.



PATENTED DEG. 4, 1906.

A. G. vITEJITIIL HANDPIECE.

APPLICATION FILED IULY1s.19oa.

SARGENT.

UNITED siiins,

PATENT oiuiici.

ALsoN c. SARGENT, .or Diis Mouans, iowa.

y DENTAL HANDPIECE. f y

tra 837,423.

Specification of Letters Patent. -i

` PatentedV Deaf 11,. 1906.

Application filed July 13, 1903- Sarial No. 165,295.l

Td @ZZ whm it may concern#4 'Be it knownthat I, ALsoN C. SARGENT, a resident of Des Moines, in the county of Polk and State of Iowa, have invented certain new anduseful Improvements in Dental Handpieces, of which the following is a specifica- This invention relates to improvements in lhandpieces and it has for its object to vide a simplified and improved construction of the character referred to.

pointed out in the appended claiiiis,and the s lowing description, reference being had to the vvThe invention consists in the matters hereinafter described, and more particularly same will be readily understood from the folaccompanying drawings, in which- Figure 1 is an axial sectional view of ahandpiece embodying my invention. Fig. 2 is a similar viewof the tool-holding end thereof on a larger scale. Fig. 8 is a cross-sectional -grooves or races are interposed ball-bearings 14. T ne spindle vierl taken on line 3 3 of Fig. 2, and Fig. 4 isa cr s-sectional view taken on line 4 4 of Fig. 2.

eferring to the drawings, 1 designates the main outer casing of lthe handpiece, which comprises a central main portion 2, a forward end ca p 3, detachably screwedto the main portion, and a-'iear end cap 4, arranged to telescope upon the corresponding end of 3o the main casing and also having screw- -threaded engagement therewith. Vithin 9 extends throughout the length ofthe handpiece and at its forward end engages anbearing in the end of the capmember 3, said cap member being to this end provided -witn an axial bore 15 and the conical seat of stepbearing 16 surrounding said bore interiorly, wit-hin and against which bearings the correspondingly-shaped portions 17 and 18 of the spindle sit.

. The end of the spindle is axially bored, as

indicated at 19, to receive the shank of a dental tool and is also provided with a plurality of radially-disposed or mortises 20,

(three in the present instance) disposed at equal angular distances vapart and constructed to accommodate a set of chuck-jaws 21. The chuck-jaws are of peculiar construction, being freely movable radially within the slots or mortises, but prevented from movinginwardly beyond a predetermined point by means of shoulders 22, formed u-pon their ends and overlying and engaging corresponding shoulders 23, 'formed in the ends of the mortises. The corners formed at ythe junction of the inner faces of the jaws with their forward end-faces are rounded, as indicated at 24, to facilitate the entrance of the shankv of the tool into position between the jaws.4 v y The chuck-jaws are each wedge-shaped or of increasing width radially from their rear or inner ends forwardly throughout. their rincipal lengths. The taper of the jaws is,

owever, comparatively slight, the tapering portion 25 shown in the drawings being considerably exaggerated in order to be more clearly perceptible. jaws which engage the shank of the toolare straight in longitudinal directions and pref- The inner faces of the erably curved in cross-section. as indicated at 26 in Figs. 3 and 4.

27 designates a chucking-sleeve which is arranged to fit upon the spindle throughout its principal length andat its forward end telescopes partly over. or upon the wedge-shaped jaws 21. In orde'rthat the forward end of the chucking-sleeve may thus fit overthe jaws, it is made slightly daring interiorly at its forward end, the flare being preferably of the same angular degree of taper as the portions of the jaws engaged thereby. In this .connection it is to be noted-that the outer edges or surfaces of the jaws engagedby the chucking-sleeve are rounded, as indicated at l.

28, to conform to the internal shape of the sleeve.

At its opposite end the ohucking-sleeve is provided with an'annulargroove 29, which.

preferably and as .shown in the present instance, is formed in an enlargement or collar 80. 31 designates a sleeve-like slide mounted upon the exterior 'l of the hand iece around the grooved portion of the chuc 'ngsleeve and connected with the; latter by means of a pair of screw-studs 32, varranged in diametrically opposite relation and ex- IOO tending through slots 38, formed in the outer'` casing. Preferably, in order to reduce the friction and lessen the rasping noise' or vibration, lthe screwuu-ds do not directly engage the annular groove of the chucling-sleeve; but a brass or analogous soft-metal collar 34- is seatedin said groove 29, landthescreW- studs engage suitable sockets formed in 'said collar.

The operation ofthe handpiece construct- 'edas described Will be entirely obviouswithout further description. It is to be. noted,

however, thatby'reasonofthe bearings .p'rovided at' theextreme ends of the' spindle by lhandpiece regardless of Wear.

i with a means ofthe adjustable bearing-plug the' spindle may be confined With the greatest accuracy and` freedom from lost motion, While `at the same time its freedom of rotation is not interfered With. This condition lobtains throughout the entire life of the It is also to be especially noted that by reason of the pro vision of the ball-bearings between the confining-cap 4 and the end ef. thebearing-plug the lattermay be adjusted to holdvthe spin; dle'with the utmost nicety and the 'coniining- Y With said jaws.

- Ihave found in practice that by reason of thelong and relatively slight tapering'fit be-A tween the chucking-sleeve and jaws'fthis 4method of fastening is entirely reliable and that the chuck-jaws accommodate them-- selves toshanks 'of varying dimensions with erfect facility. This`feature is one of great importance, since I am' thus enabled to simplify the tool as a Whole' te a minimum'num- .I ,i cheapz and durable con-struc tion.

er of parts, all of which parts 'are of simple,

Another feature of improvement` resides in so constructing the forward end capl that it is removable and separates from the main shell. at apoint .back of the-chuck, Vso that when said Ycap,isrenioved the chuck is fully exposed. This I feature is of 'impertanca since it not only enables me to clean and oil thespindle-'bearing in this end ofthehand- A piece, but it also affords the greatest free domof accessdto the chuck. for the purpose A embracingend'of the chucling-sleev'e acting of cleaning and inspecting the latter. In vthis connection itis-'to be noted. thatv the in conjunction With the peculiar-sliaped notches crshoulders in the .ends of the inortises prevents the jaws' from becoming displaced When'the tool is removed and the end v vcap taken off, unless the chucking-sleeve be deliberately retracted to approximately 'its y full extent. .Y y

While I have herein shown and described what I deem to be a preferred embodiment of the'invention, yet the details thereof may bemodified Without departing from the in-- l vention, and I do not, therefore, limit myself .to these details, except to the extent that they formthe subject of specific claims.

I' claim as my invention-' v ,l 1. In a dental handpiece, the combinationof a tool-holding spindle provideddnjith` an axial bore to receive the shank of a Ifool land with a plurality of mortises extending through the sides of the spindle into said bore, chuck-jaws loosely seated in said inor-` -tises each havingv a substantially straight vinner face andv a `forwardly` and outwardly vinclined outer face ,protruding radially be- X yond the spindle, the ends .of said Vmortises and of saidv chuck-jaws-'being providedwith interiitting shoulders, achuck-sleeve mount ed te slide upon the spindle and having'its forward end telescoping upony and engaging the outnf'ari'lly and forwardly inclined surfaces of the chuck-jaws, anexternal slide upon the handpieec, and operative ,connections between said slide and said chucksleeve.

2. In'a dental handpiece,

mounted to extend therethrough, saidwspindle having a shouldered vand reduced krear they combina'- tion of a tubular outer casing, a spindle end, and bearings for they'opposite ends of said spindle comprising `a relativelytiiied lforward end bearing and an,adjustableir'ear end bearing consisting of an axially-bo redy screw-plug mounted upon ,the reduced rear endof the spindle and threaded into `the end of the outer casing, and an end cap inc-losing said screw-plug and threaded upon-thee):-

terior of the outer casing, substantiallyfas described.

3. .In a dental handpiece, the combination of a tubular outer casing, a .spindle nicunted to extend.v therethrough,and been ings for the vopposite ends of said spindle comprisingl a relatively fixed fcrwarlzfend Vbearing and an adjustable rear vend, bearing consisting of a screwfplug threaded linterim end of the outer casing, an end cap incidanig said screw-plug, surrounding lthe spindle and threaded uponthe exterior jof. the o u'er casing, and antifrictionebearings interposed between the. opposed portions of the sereni-f plug and end cap, substantially as described. .ALSGN C. SARGENI, iitnesses: Y

ALBERT, Il'. Gnavss, lil-nnnnnicr: e C. Gconwix,

IIb 

